This is the prototype of my solution. Seems to work pretty well.
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Nes Freak wrote:
so you went wit hthe face down method 😛 nice looking foward to trying these out 😛 will the solder be pre on the pads? if so make sure its leaded and tin 60 40 sodler not lead free sodler. lead free solder can grow tin wiskers
The fab house I use does not offer pre-tinning options on flex cables, and the next cheapest fab house that does requires a $2000 setup and tooling fee. That sort of cost for something that only saves the user 20 seconds isn’t a good tradeoff for me.
I’ve sent this design out for prototyping. The fab house I use for prototypes takes a lot longer to produce small runs, so I don’t know when I’ll get it.
This is the more ‘conventional’ solution of addressing the issues with my v1.7 VirtualCables. I’m keeping my really exciting solution under wraps until and unless I get all my materials and test pieces in and guarantee an easy, solid solution.
Changes from v1.7:
– Change from a Type B cable (connective ends on opposing layers) to Type A (connective ends on same layers). This means the end of the ‘normal’ installation method of pulling solder up and over pins, and the official adoption of the ‘revised’ installation method, whereby the user applies the soldering iron to the back side of the cable in order to heat the pads, thereby melting the solder and creating an incredibly strong mechanical/electrical connection.
– Removal of castellated holes from 0.6mm-pitch side. They have been replaced by normal holes, intended for orientation rather than connection. There simply wasn’t enough metal mass on the cable ends to form a good connection with castellations.
– Addition of pads for unconnected pads on board. I determined it was too easy for a user to simply miscount or slip while soldering, so the additional 6 dummy pads have been re-introduced in order to eliminate potential installation pitfalls.
– Introduction of test point vias. With the adaptation of the revised installation method, users need an easy way to make sure that their connections are good. Thus, each signal is given an individual, un-tented via (including both GND signals, though this is more for symmetry rather than effect) so that users may quickly and efficiently test each soldered connection one-by-one.
– Elongation of the Motherboard-Side Stiffener. The v1.7 Stiffener was determined to be useable, but too short for comfort or ease-of-use. Therefore, the length of the stiffener has been tripled, which should allow for a comfortable ZIF experience.
– Castellated cutouts for stability. On the LED board, the outermost pads branch out into geometric designs. Utterly useless for its intended function, but by introducing unconnected castellated cutouts, users will be able to orient the cable and use those stylistic pads to tack the cable in place without the possibility of damaging anything by having to remove and resolder a poorly oriented cable.
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At the Post Office right now, halfway through. Filling out customs declarations en masse is not fun. I’ll send each buyer a copy of their customs receipt when I get home.
Phew.
It appears that I have 14 pairs of cables available from buyers who did not pay. I’m holding on to four of them, but the other ten are first come first serve. I’m going to try a new installation method for the current cables that might be easier and more importantly, create a stronger bond. I’ll update the thread as I figure things out.